python - 如何在按键事件后将函数blit到屏幕(pygame)

Question

我试图通过按空格键将屏幕从介绍屏幕切换到说明屏幕。但是，当您按空格键时，说明屏幕仅在您按下时保持打开状态

    for event in pygame.event.get():
    intro_screen()
    if event.type == pygame.KEYDOWN:
        if event.key == pygame.K_SPACE:
            instructions()
            pygame.display.flip()

我该如何解决这个问题，让它最后出现在屏幕上？另外，我是否可以使用同一个按键来显示不同的功能？

我是 pygame 新手:)

Answer 1

代码需要维护显示的状态。目前，主循环似乎总是绘制“介绍屏幕”，并且正如您所说，仅在空格键事件上绘制“说明屏幕”。这也被放入事件处理程序代码中，它可能应该位于该部分之外。

for event in pygame.event.get():
    intro_screen()                               # <-- Draw intro
    if event.type == pygame.KEYDOWN:
        if event.key == pygame.K_SPACE:
            instructions()                       # <-- Draw Instructions
        pygame.display.flip()

最好将要显示的屏幕存储在变量中。

current_screen = 'introduction'              # enumerated type would be better
done = False

# main loop
while not done:
    # handle events
    for event in pygame.event.get():
        if ( event.type == pygame.QUIT ):
            done = True
        elif ( event.type == pygame.KEYDOWN ):
            if ( event.key == pygame.K_SPACE ):
                current_screen = 'instructions'    # switch screens
            elif ( event.key == pygame.K_BACKSPACE ):
                current_screen = 'introduction'    # switch screens back

    # paint the screen
    if ( current_screen = 'introduction' ):
        intro_screen()                             # draw the introduction screen
    elif ( current_screen = 'instructions' ):
        instructions()                             # draw the instructions
    else:
        # TODO - more screen types
        pass

    pygame.display.flip()